<style>
    .sidebar > ul > li {
        padding: 10px 20px;
        border-bottom: 1px solid #e7e7e7;
        text-align: center;
    }

    .sidebar > ul > li > a {
        color: #428bca;
        text-decoration: none;
    }

    .sidebar > ul {
        margin: 0;
        padding: 0;
    }

    .sidebar_img  img {
        width: 100%;
        height: 100%;
        border: 2px solid #ccc;
        border-radius: 10%;
    }

    .sidebar_img {
        display: inline-block;
        position: relative;
        width: 70px;
        height: 70px;
        overflow: hidden;
        border-radius: 10%;
    }
</style>

<div class="sidebar">
    <ul>
        <li>
            <div class="sidebar_img">
                <a href="/" target="_blank">
                    <img src="https://blog.dbsgw.com/admin/views/images/avatar.jpg"
                         alt=""></a>
            </div>
        </li>
        <li><a href="/admin/write">写文章</a></li>
        <li><a href="/admin/admin">文章</a></li>
        <li><a href="#">标签</a></li>
        <li><a href="/admin/sort">分类</a></li>
        <li><a href="#">页面</a></li>
        <li><a href="#">友链</a></li>
        <li><a href="#">外观</a></li>
        <li><a href="#">系统</a></li>
    </ul>
</div>